how to test transformer windings?

To test transformer windings, you can perform several key tests. First, use a multimeter to check for continuity and resistance across the windings, ensuring there are no open circuits. Next, conduct an insulation resistance test with a megohmmeter to verify insulation integrity. Additionally, perform a turns ratio test to confirm the winding ratios are correct. Finally, a power factor test can assess the condition of the insulation under operational conditions.